KR102381094B1 - Process for making cationic polymers with reduced halide content - Google Patents

Abstract

The present invention relates to a process for obtaining water-soluble cationic polymers P1 with reduced halide content, as well as in compositions based on mineral binders or in aqueous open, semi-closed or closed circuit treatment. to the use of said polymer as an additive in

Description

Process for making cationic polymers with reduced halide content

An object of the present invention relates to a process for preparing polymers for the preparation of water-soluble cationic polymers having a high positive charge density and a reduced halide content.

It is also an object of the present invention to prepare the abovementioned water-soluble cationic polymers as additives in compositions based on inorganic mineral binders or gypsum derivatives, or in the treatment of open, semi-closed or closed aqueous circuits. It's about use.

Water-soluble cationic polymers with high charge density and low viscosity are known to those skilled in the art and can be obtained by various methods.

For example, the polycondensation reaction of a difunctional amine compound, such as an alkylene amine, or a primary or secondary monoamine with a difunctional compound selected from diepoxide, epihalohydrin or di-halogen compound can be mentioned

It is a known practice from US 3 738 945 and US 3 725 312 to use a monomeric entity, preferably having a molecular weight as small as possible, in order to meet the criterion of high positive charge density; Ammonia or mono- or di-alkylated amines are preferred entities.

However, the use of ammonia or mono-alkylated amines results in structured polymers (branched), where even if the viscosity of these polymers is less than 200 cps, the positive charge is sterically inaccessible very weakly, and thus these branched The structure is minimally preferred.

Accordingly, in order to obtain linear polymers of low molecular weight, the person skilled in the art will preferably use di-alkylated amines, of which dimethylamine is preferred.

For the polycondensation reaction, epihalohydrins, preferably epichlorohydrins, are generally preferred over di-epoxides because they have a lower molecular weight and thus the preparation of cationic polymers with a high positive charge density is difficult. it becomes possible However, the cationic polymer thus obtained is characterized by a high halide content.

The use of dihalogenated compounds, such as dichloroethane, is also known from document US 4 057 580 for the preparation of polymers characterized by a very high cationic halide content.

A quaternary ammonium functional group that may be selected from acrylamidopropyl trimethyl ammonium chloride (APTAC), methacrylamido propyl trimethyl ammonium chloride (MAPTAC), dimethylaminoethyl acrylate (DMAEA) or dimethylaminoethyl methacrylate (DMAEMA) The radical polymerization of one or more ethylenic monomers with

Another method for preparing water-soluble cationic polymers with high positive charge density and low viscosity known to those skilled in the art is the radical polymerization of one or more allyl monomers, such as diallyl dialkyl ammonium halides. Among allyl monomers, diallyl dimethyl ammonium halide makes it possible to obtain the highest charge density polymers, and the most accessible said allyl monomer on the market is diallyl dimethyl ammonium chloride (DADMAC). Polymers containing DADMAC are characterized by a high chloride content. In particular, DADMAC homopolymers are characterized by a chloride content of greater than 10%, typically greater than 20% by weight of the polymer.

All these water-soluble cationic polymers with high charge density are universally used as additives in compositions based on inorganic binders (calcium sulfate in more or less hydrated form, such as cement, plaster, gypsum or anhydrite), or in occlusive or Used as a coagulant in semi-closed circuits (eg papermaking, mining sector methods and processes).

More precisely, in the field of construction, it contains cement, aggregate, lime, plaster, slag, such as concrete, mortar, coatings, and therefore hydraulic and air (non-hydraulic). ) Compositions based on inorganic mineral binders, known as binders, often contain clays such as drilling muds used for cementing wells in terms of extraction of oil and gas. However, these clays have a lamellar structure that can absorb water or certain additives, leading to poor performance of the building/drilling material (cracking due to swelling of the clay, flow problems, gelation problems, etc.) .

Thereafter, it is known to use a water-soluble cationic polymer having a high positive charge density as a moderation agent (also known as an inerting agent or inertant for clay) to moderate the effect of the clay. it has been implemented. Documents US 6 352 952, US 2013/0035417 and EP 2 414 460 therefore disclose the use of cationic polymers for ameliorating the effect of clays in cementitious compositions.

When the clays are non-swellable clays, these clays can have a detrimental effect on the performance of the building material. A practice also known from document US 2013/0035417 is the use of cationic polymers as emollient agents for ameliorating the effects of these non-swellable clays.

In addition, the presence of clays in compositions based on hydraulic binders - more particularly for building materials derived from gypsum (calcium sulfate in anhydrous form, hemi-hydrate or di-hydrate form) - is known to lead to degradation of the performance of these materials. To deal with this, it is a known practice from document US 8 906 986 to use quaternary amines as emollient agents for softening the clay in order to maintain the performance level of the super-plasticizer contained in the formulation.

Finally, the use of functionalized cationic polymers due to polycondensation between epihalohydrin and dialkylamines to mitigate the effect of clays on aggregate is known from document US 2015/0065614.

However, all of the water-soluble cationic polymers described in the art for this use are characterized by high halide content, which is problematic. In fact, the presence of halides in the composition, in particular the presence of chlorides, results in corrosion of metallic materials with which these halides come into contact, such as metal frameworks and fittings (Corrosion of Steel in Concrete: Prevention, Diagnosis, Repair, 2nd Edition, Luca Bertolini).

In addition, when these water-soluble cationic polymers are used in closed or semi-closed circuit systems, they may encounter the accumulation of halides within the circuit, thus precipitating and/or precipitating salts present in the circuit. Conductivity-related problems may arise.

Accordingly, a need currently exists to prepare water soluble cationic polymers having high positive charge density, low viscosity and reduced halide content, said water soluble cationic polymers reducing or reducing the corrosion and/or precipitation phenomena encountered during their use. Or even get rid of it.

Accordingly, one object of the present invention is to provide a process for preparing polymers for the preparation of cationic polymers having high positive charge density, low viscosity and reduced halide content.

Another object of the present invention is to ensure the availability of water-soluble cationic polymers to reduce or even eliminate corrosion and/or precipitation phenomena encountered during use of these water-soluble cationic polymers.

Accordingly, the present invention relates to a polymer for the preparation of aqueous solutions of water-soluble cationic polymer P1 characterized by a halide content of less than 10% by weight of the polymer, a viscosity of less than 200 cps at 25° C., and a positive charge density of at least 4 meq.g ⁻¹ . It relates to a process for the preparation, wherein this viscosity is determined for an aqueous solution of polymer P1 concentrated at 50% by weight, said process comprising the steps of:

a) adding at least one compound of formula (I) to an aqueous solution of at least one water-soluble cationic polymer P2 at a temperature between 0° C. and 120° C. to obtain a mixture, wherein the halide content is 10% by weight of the polymer is greater than, the viscosity is less than 200 cps at 25° C., this viscosity is determined for an aqueous solution of polymer P2 concentrated at 50% by weight, the positive charge density is at least 4 meq.g ⁻¹ , the compound of formula (I) is Formula: R ¹ -COO ^- Y ₁ ⁺ , wherein:

- R ¹ represents a hydrogen atom or a linear or branched saturated alkyl chain comprising 1 to 8 carbon atoms and which may contain one or more nitrogen and/or oxygen atoms, said chain of the formula -COR may be substituted by 1 to 4 carboxylate functional groups;

- Y ₁ ⁺ represents an alkali metal cation, ammonium of the formula R ² -NH ₃ ⁺ or quaternary ammonium of the formula R ³ -N ⁺ (R ⁴ )(R ⁵⁾ (R ⁶ );

- R represents an OH group or an O ^- Y ₂₊ group ^;

- Y ₂ ⁺ represents an alkali metal cation or ammonium of the formula R ² -NH ₃ +;

- R ² represents a hydrogen atom or a linear or branched saturated alkyl chain comprising 1 to 4 carbon atoms;

- R ³ , R ⁴ , R ⁵ and R ⁶ represent, independently of each other, a linear or branched saturated alkyl chain comprising from 1 to 4 carbon atoms;

b) agitating the mixture obtained in step a) for at least 5 minutes to obtain a stirred mixture;

c) reducing the temperature of the stirred mixture obtained at the end of step b) at a temperature of -10°C to 50°C to obtain a cooled mixture; and

d) liquid/solid separation of the cooled mixture obtained at the end of step c) to obtain an aqueous solution of the cationic polymer P1

includes

According to the present invention, a polymer is said to be "cationic" when it has at least one cationic group. As the cationic group, mention may be made, for example, of an ammonium group or a phosphonium group.

According to the present invention, a polymer is said to be "water-soluble" if, when concentrated to 50 gL ^-1 , it is possible to obtain an aqueous solution which does not contain any insoluble particles after dissolution as a result of stirring.

According to the present invention, "halide content" is defined as the ratio of the total molar mass of halide to the molar mass of the cationic polymer.

For example, halide content can be determined by ion chromatography or elemental analysis.

Preferably according to the invention, the halide content is that of chloride.

According to the invention, for example, the chloride content of the water-soluble cationic polymers P1 or P2 is quantified by ion chromatography. The apparatus used is a Metrohm Ion Chromatography 850 Professional IC equipped with an 896 conductivity detector and a Metrosep A Supp5 250/4.0 column. Assay conditions were a flow rate of 0.7 mL/min, an assay period of 35 min, a column temperature of 35°C, an injection volume of 25 μL, and a mobile phase consisting of an aqueous solution of 3.2 mM sodium carbonate and 1 mM sodium bicarbonate. is composed of The internal standard is sodium bicarbonate.

According to the present invention, "viscosity" is the kinematic viscosity measured during a shear of 7.34 s ^-1 at 25°C.

According to the invention, the viscosity of the water-soluble cationic polymer P1 or P2 can be determined by means of an apparatus such as Kinexus Pro2 from Malvern© for an aqueous solution containing 50% by weight of polymer P1 or P2. The device is equipped with a 2° cone-plate module. 2.3 mL of polymer P1 or P2 solution is placed in a controlled measuring cell at 25° C., and its shear is 7.34 s ⁻¹ . Viscosity is the average of 10 viscosity measurements taken every 20 seconds.

According to the present invention, the positive charge density of a polymer is defined as the ratio of the total number of positive charges of said polymer to the molecular weight of said polymer.

According to the present invention, the positive charge density of a water-soluble cationic polymer can be determined by a colorimetric assay using potassium polyvinyl sulfate (KPVS) in the presence of a colored indicator (toluidine blue) according to the following protocol:

A cationic polymer solution is prepared at a concentration of 5 gL ^-1 in deionized water (stock solution). Sample 1 g of this stock solution and then dilute in 100 mL of deionized water (solution 1). Add 0.1 N hydrochloric acid to solution 1 to adjust the pH to 4. Subsequently, 3 drops of an aqueous solution of toluidine blue at a concentration of 0.1% are added. In this way, solution 2 is obtained.

At the same time, a graduated burette of the KPVS solution is prepared at N/400, with a known correction factor f, after which it is added dropwise to solution 2. When the color of solution 2 changes from blue to purple and this purple color lasts for several seconds, check the dose. The milliliter volume of KPVS solution is denoted by V.

Thereafter, the positive charge density of the polymer is determined by the formula:

.

.

The positive charge density is expressed as meq.g ^-1 .

According to the invention, "liquid/solid separation" is a step which consists in separating insoluble compounds of a solution of polymer P1.

According to the present invention, an "insoluble compound" is a compound resulting from the process of the present invention which is not soluble in water.

For example, the content of the insoluble compound contained in the solution of the water-soluble cationic polymer P1 is determined by filtration of the solution of the polymer P1 on a filter, the porosity of the filter being 6 μm or less. After such filtration, the filter collecting insoluble particles is placed in an oven at 500° C. for 2 hours. The percentage of insoluble compounds contained in the solution of polymer P1 is defined as the ratio of the mass of particles collected on the filter after drying to the mass of the solution of polymer P1 before filtration.

Preferably, the polymer P1 of the present invention is a water-soluble cationic polymer characterized by a chloride content of less than 10% by weight of the polymer, a viscosity of less than 200 cps at 25°C, and a positive charge density of at least 4 meq.g ⁻¹ , wherein The viscosity is determined for an aqueous solution of polymer P1 concentrated at 50% by weight.

Preferably, the polymer P1 of the present invention has a chloride content of less than 10% by weight of the polymer, a viscosity of less than 200 cps at 25°C, a positive charge density of at least 4 meq.g ⁻¹ , and less than 2% relative to the total weight of the polymer. is a water-soluble cationic polymer characterized by the mass content of insoluble compounds of

Preferably, the polymer P1 of the present invention is a water-soluble cationic polymer characterized by a chloride content of less than 10% by weight of the polymer, a viscosity of less than 200 cps at 25°C, and a positive charge density of at least 5 meq.g ⁻¹ , wherein The viscosity is determined for an aqueous solution of polymer P1 concentrated at 50% by weight. Preferably, the polymer P1 of the present invention has a chloride content of less than 10% by weight of the polymer, a viscosity of less than 200 cps at 25° C., a positive charge density of at least 5 meq.g ⁻¹ , and less than 2% relative to the total weight of the polymer. is a water-soluble cationic polymer characterized by the weight content of insoluble compounds of

According to one preferred embodiment, the polymer P1 of the invention is a water-soluble cationic polymer characterized by a positive charge density of at least 6 meq.g ^-1 .

The viscosity at 25° C. of the polymer P1 obtained according to the process of the invention is less than 200 cps, said viscosity being determined for an aqueous solution of the polymer P1 concentrated at 50% by weight. Preferably, the viscosity at 25° C. of polymer P1 is less than 150 cps, preferably less than 100 cps, said viscosity in an aqueous solution of polymer P1 concentrated at 50% by weight relative to the concentration of 50% active water-soluble polymer in solution. is decided about

Polymer P2 used in the process of the present invention is a water-soluble cationic polymer characterized by a chloride content of greater than 10% by weight of the polymer, a viscosity of less than 200 cps at 25°C, and a positive charge density of at least 4 meq.g ⁻¹ , wherein The viscosity is determined for an aqueous solution of polymer P1 concentrated at 50% by weight.

Preferably, the aqueous solution of at least one water-soluble cationic polymer P2 used in step a) of the process of the invention is concentrated to a maximum of 80% by weight relative to the total weight of said solution. The viscosity at 25° C. of an aqueous solution of at least one hydrosoluble cationic polymer P2 concentrated to 80% by weight may be greater than 2,000 cps.

The positive charge density of the polymer P2 used in step a) of the process of the invention is at least 4 meq.g ⁻¹ . Preferably, the positive charge density of polymer P2 is at least 6 meq.g ^-1 .

The viscosity at 25° C. of the polymer P2 used in step a) of the process of the invention is less than 200 cps. Preferably, the viscosity at 25° C. of polymer P2 is less than 100 cps, even more preferably less than 50 cps, said viscosity being determined for an aqueous solution of polymer P2 concentrated at 50% by weight.

In a preferred mode according to the invention, during step a), the ratio of the number of negative charges of the compound of formula (I) to the number of positive charges of the water-soluble cationic polymer P2 is from 0.2:1 to 5:1, preferably from 0.6:1 to 2:1.

The number of negative charges in the compound of formula (I) is defined as the sum of the number of functional groups -COO ^- Y ₁ ⁺ and -COO ^- Y ₂ ⁺ .

In an advantageous manner according to the invention, the temperature during step a) is between 0°C and 120°C, preferably between 10°C and 95°C, even more preferably between 15°C and 80°C.

In a preferred mode according to the invention, the compound of formula (I) used in step a) is a compound in which R ¹ represents a hydrogen atom or a methyl group.

Preferably, in the aforementioned formula (I), Y ₁ ⁺ is selected from alkali metal cations, in particular sodium, potassium or lithium.

Preferably, in the aforementioned formula (I), Y ₁ ⁺ is NH ₄ ⁺ .

In an advantageous manner according to the invention, the compound of formula (I) is selected from sodium formate, potassium formate, sodium acetate and potassium acetate. Preferably, the compound of formula (I) is selected from potassium formate and potassium acetate.

Also in an advantageous manner according to the invention, the water-soluble cationic polymer P2 used in step a) of the process of the invention comprises at least one ethylenic monomer having a quaternary ammonium function, quaternised with a halogenated alkyl derivative; for example radical polymerization products of acrylamido propyl trimethyl ammonium chloride (APTAC), methacrylamido propyl trimethyl ammonium chloride (MAPTAC), dimethylaminoethyl acrylate (DMAEA) or dimethylaminoethyl methacrylate (DMAEMA).

In a preferred manner according to the invention, the water-soluble cationic polymer P2 used in step a) of the process of the invention may be selected from radical polymerization products of allyl monomers, such as diallyldialkyl ammonium halides.

In a preferred manner according to the invention, the polymer P2 obtained by radical polymerization used in step a) of the process is derived from the polymerization of one or more monomers of the type such as diallyldialkyl ammonium halide. Preferentially, the polymer P2 used in step a) is obtained by radical polymerization of diallyl dimethyl ammonium chloride (DADMAC).

In an advantageous manner, the water-soluble cationic polymer P2 used in step a) of the process according to the invention comprises (meth)acrylamide, N,N-dialkyl (meth)acrylamide, hydroxy alkyl esters of (meth)acrylic acid, N-vinyl pyrrolidone, N-vinyl formamide, methacrylate of polyethylene glycol, methacrylate of propylene glycol, isoprenyl of polyethylene glycol, isoprenyl of propylene glycol, ether of polyethylene glycol and vinyloxybutyl; It can be obtained by radical copolymerization with one or more nonionic monomers selected from allyl ethers of polyethylene glycol or propylene glycol. In a preferred manner according to the invention, the water-soluble polymer P2 used in step a) of the process according to the invention can be obtained by radical polymerization of one or more nonionic monomers, such as acrylamide.

In an advantageous manner, the water-soluble cationic polymer P2 is subjected to radical copolymerization with at least one anionic monomer selected from monomers comprising at least one carboxyl function, such as (meth)acrylic acid, itaconic acid, fumaric acid, maleic acid and salts thereof. and the monomers include sulfonic acid functional groups such as 2-acrylamido-2-methylpropane sulfonic acid (AMPS), vinylsulfonic acid, allylsulfonic acid, styrenesulfonic acid and salts thereof. . Preferably according to the invention, the water-soluble polymer P2 used in step a) of the process according to the invention is at least one anionic monomer selected from acrylic acid and 2-acrylamido-2-methylpropane sulfonic acid and salts thereof It can be obtained by radical polymerization of

The radical polymerization which makes it possible to obtain the water-soluble cationic polymer P2 can be initiated by various techniques known to the person skilled in the art. The first technique is the use of initiators such as peroxides, persulfates, azo derivatives or oxidation/reduction couples. photo-initiated, controlled radical polymerization, atom-transfer radical-polymerization (ATRP), radical polymerization in the presence of nitroxide (NMP), or by reversible addition-fragmentation chain transfer (RAFT) Other techniques such as controlled radical polymerization may also be used.

International patent application WO 2008/000766 describes modifiers used for RAFT type controlled radical polymerization. In a preferred manner according to the invention, when this type of polymerization is selected, the modifiers for the RAFT polymerization are xanthates, dithioesters, trithiocarbonates, dithiocarbamates, dithiocarbazates and dithiophos. sporoesters.

In an advantageous manner according to the invention, the preferred regulator used for preparing the water-soluble cationic polymer P2 by RAFT type polymerization is O-ethyl-S-(1-methoxycarbonyl-ethyl) xanthate.

In an advantageous manner according to the invention, the water-soluble cationic polymer P2 operatively applied in step a) is a polycondensation product of at least one epihalohydrin and at least one secondary amine, preferably said water-soluble cationic polymer P2 is the polycondensation product of epichlorohydrin and dimethylamine.

Preferably, when this reaction is used for the preparation of P2, the stoichiometric ratio between dimethylamine and epichlorohydrin is from 1:0.99 to 1:0.80, preferably from 1:0.95 to 1:0.85. This ratio is also described in US Pat. No. 4,569 991.

In a preferred manner according to the invention, during step b) of the process of the invention, the mixture obtained at the end of step a) is at least 5 minutes, preferably from 5 minutes to 360 minutes, more advantageously from 30 minutes to 360 minutes placed under agitation for a period of

In a preferred manner according to the invention, during step b) of the process of the invention, the mixture obtained at the end of step a) is stirred by mechanical or magnetic means.

In a preferred manner according to the invention, during step c) of the process of the invention, the temperature of the stirred mixture obtained at the end of step b) is advantageously from -10°C to 50°C, preferably from 0°C to lowered to 40 °C.

Preferably, the liquid/solid separation in step d) of the process of the invention is a decantation or filtration process. Preferably, if this liquid/solid separation is carried out by filtration, this filtration is carried out by means of centrifugation, a belt filter, a press filter or a plate filter.

Preferably according to the invention, the liquid/solid separation in step d) makes it possible to obtain an aqueous solution of the water-soluble cationic polymer P1 comprising less than 2% by weight, more preferably less than 1% by weight of insoluble compounds .

The amount of insoluble compound is directly related to the amount of halide contained in the aqueous solution of polymer P1. Thus, the lower the content of insoluble compounds, the lower the content of halides that will be present in this polymer.

In an advantageous manner, the process according to the invention may comprise step e) subsequent to step d) of the process of the invention. Preferably, the process according to the invention comprises a step e) of drying the aqueous solution of the water-soluble cationic polymer P1 obtained at the end of step d).

Preferably, at the end of step e), the water-soluble cationic polymer P1 is in solid form. Any suitable drying method known to the person skilled in the art can be used by carrying out step e) of the method of the present invention. Preferably, the drying method is selected from the following drying methods: by spray drying, via a drum dryer, or by electromagnetic waves such as microwaves, infrared waves or radio waves.

The insoluble cationic polymer P1 in solid form obtained at the end of step e) of the process according to the invention, once dried, can be dissolved in aqueous solution to the desired concentration for its subsequent use. The water-soluble cationic polymer P1 may also be in powder form. When the polymer P1 is used in powder form, it may be partially or wholly dissolved, or may remain in solid form during its use.

The invention also has the potential to be obtained by the process according to the invention, in which respect the halide content is less than 10% by weight of the polymer, the viscosity is less than 200 cps at 25° C. and the charge density is 4 meq.g ^{- 1} or more, wherein the mass content of insoluble compounds is less than 2% by weight of water-soluble cationic polymer P1, said viscosity being determined for an aqueous solution of polymer P1 concentrated at 50% by weight.

According to one preferred embodiment, the present invention also relates to the use of a water-soluble cationic polymer P1, possibly obtainable by the process according to the invention, the charge density of which is at least 6 meq.g ^-1 .

In a preferred manner according to the invention, the water-soluble cationic polymer P1 obtained by the process of the invention is used as an additive in compositions based on inorganic mineral binders or gypsum derivatives.

In particular, the present invention relates to the use of polymer P1 as hereinbefore defined, having a charge density of at least 6 meq.g ^-1 , for mitigating the effect of clays in compositions based on inorganic mineral binders or gypsum derivatives. It relates to use as an emollient agent.

According to the present invention, a composition based on a mineral binder is defined as a composition comprising one or more inorganic mineral binders such as calcium sulfate, which may be present in somewhat hydrated form (cement, plaster, gypsum or anhydrite). According to the invention, such a composition can be used in the field of construction. According to the invention, this composition may also comprise one or more clays.

According to the present invention, a gypsum derivative is defined as being calcium sulfate in anhydrous form, in hemi-hydrate form or in di-hydrate form. Thus, according to the present invention, a composition based on a gypsum derivative is defined as comprising calcium sulfate in anhydrous form, in hemi-hydrate form or in di-hydrate form, which is a composition for use in the field of construction. In a further preferred manner, the water-soluble cationic polymer P1 obtained by the process of the invention is used for treatment in an open, semi-closed or closed aqueous circuit. Preferably, the water-soluble cationic polymer P1 obtained by the process of the invention is used for the treatment of closed or semi-closed circuits and systems.

According to the invention, the water-soluble cationic polymer P1 obtained according to the process of the invention can be used as an additive in aggregate (sand, gravel, rock and cobblestone, cement), concrete or mortar (coatings, plasters) in the field of construction. there is.

According to the present invention, a closed or semi-closed circuit may contain a metal element (conduit) and may contain at least a portion of the outflowing stream to be recycled into the inflowing stream. is a circuit of As closed or semi-closed circuits, mention may be made of plants for the treatment of rainwater/stormwater, domestic/domestic or industrial wastewater, plants involved in papermaking or mining related processes, drilling rigs and plants and metalworking plants.

According to the present invention, an open circuit is any circuit that may contain metallic elements and the effluent stream is not recycled into the inlet stream. As an open circuit, reference may be made to plants involved in processes (autoclaving) used in the construction, electronics and wood processing sectors.

The water-soluble cationic polymer P1 obtained by the process of the invention is characterized by a reduced halide content. Thus, the advantages associated with the use of these polymers in aqueous open, closed or semi-closed circuits are their reduced is corrosive. A further advantage of using the water-soluble cationic polymer P1 obtained by the process of the invention in closed or semi-closed circuits is the reduced accumulation of halides in these circuits due to the reduced content of halides in these polymers. am.

In an advantageous manner according to the invention, if the polymers resulting from the process of the invention are used as additives in compositions based on inorganic mineral binders or gypsum derivatives, these polymers are preferably emollient agents for ameliorating the effect of clays. has a role as

According to the present invention, the term "emollient agent for mitigating the effect of clay" is understood to indicate that the agent used serves the purpose of reducing the deleterious effect of clay on building materials.

The present invention therefore also relates to the use of a water-soluble cationic polymer P1, possibly obtainable according to the process of the invention, said use for mitigating the effect of clays in compositions based on inorganic mineral binders or gypsum derivatives. wherein the receptor has a halide content of less than 10% by weight of the polymer, a viscosity of less than 200 cps at 25°C, a charge density of at least 4 meq.g ^-1 , and this viscosity is 50% by weight of the polymer. The concentration is determined for an aqueous solution of polymer P1 concentrated.

In a preferred manner according to the invention, the water-soluble cationic polymer P1 possibly obtained according to the process of the invention is particularly effective as an emollient agent for alleviating the effects of clays in compositions comprising the following clays:

- swellable clays of type 2:1, such as smectite, or swellable clays of type 1:1, such as kaolin or swellable clays of type 2:1:1, such as chlorite;

- silicates of magnesium and/or aluminum;

- phyllo silicates having a lamellar structure;

- Amorphous clay.

While not wishing to be bound by a specific list, the present invention also relates to clays generally present in sand, such as montmorillonite, illite, kaolinite or even muscovite. .

Clays absorb water, among other behaviors, and can lead to poor performance of building materials. When the cationic and water-soluble polymers P1 likely to be obtained by the process of the present invention are used as a relief agent to alleviate the effect of clay, among other features and behaviors mentioned, these polymers subsequently induce cracking and Prevents swelling of the clay that could weaken any construction. These polymers P1 also make it possible to avoid rheological problems in the formulation, which may originate from the absorption of water and/or super-plasticizing agents by the clay.

In a preferred manner according to the invention, the water-soluble cationic polymer P1, possibly obtainable by the process of the invention, is used in compositions comprising clays and acts as a emollient to alleviate the effects of these clays. The concentration of polymer P1 in this composition is from 0.1% to 100% by weight relative to the dry weight of the clay contained in the hydraulic composition to be treated. Preferably, the concentration of polymer P1 is between 0.5% and 50%, more advantageously between 1% and 30%.

Optionally, cementitious compositions based on inorganic mineral binders or gypsum derivatives are added therein to the polymer P1 possibly obtainable according to the process of the invention, and an agent limiting the contribution of water (lignosulfonates, Naphthalene sulfonate formaldehyde adduct, melamine sulfonate formaldehyde adduct), superplasticizer (comb polymer having polycarboxylate units containing ethylene oxide groups and/or propylene oxide groups), gluconate, cure delay other additives selected from set retarding agents, cure accelerators, defoamers, surface-active agents or surfactants, or heavy metal chelating agents.

In a preferred manner according to the invention, when the water-soluble cationic polymers P1 likely to be obtained according to the process of the invention are used in the construction field, these polymers are mixed with the polymer P1 present on a washer belt or on a mixer. The solution is applied directly by spraying it onto the aggregate. Alternatively according to the invention, if the polymers obtained from the process of the invention are used as additives to compositions based on inorganic binders, these polymers are used in central concrete mixing plants, concrete mixing plants or plants for pre-production of materials. either added directly to the composition or supplied by the inorganic binder used in the preparation of the composition.

The present invention also relates to the use of the water-soluble and cationic polymer P1 possibly obtainable by the process of the invention, said use as a coagulant for the coagulation of elastomers.

The effects of the methods of the invention and of the use of polymers derived therefrom are illustrated in terms of, but not limited to, the examples which follow.

Example

Example 1: Preparation of polymer P1 characterized by a chloride content of less than 10% by weight of the polymer and obtained as a result of the polycondensation of epichlorohydrin with dimethylamine

To a 1 liter reactor equipped with a jacket, condenser, mechanical stirring mechanism and temperature sensor probe, the following components: 272 g of dimethylamine (Sigma Aldrich) and 331 g of water at a concentration of 60% by weight were added did Then, 319 g of epichlorohydrin (Sigma Aldrich) was added dropwise over a period of 3 hours, while maintaining the temperature between 70°C and 80°C.

Thereafter, approximately 80 g of water at 50° C. was added to the mixture to adjust the concentration of the polymer formed to 50% by weight.

The polycondensation product obtained - known as polymer A - is characterized by a positive charge density of 7 meq.g ^-1 , a viscosity of 30 cps at 25° C., and a chloride content of 25% by weight of the polymer, this viscosity being 50% by weight was determined for an aqueous solution of polymer A concentrated to %; These values were determined according to the protocol as previously defined.

500 g of polymer A were introduced into a thermostatically controlled 1 liter reactor equipped with a jacket, magnetic stirrer, condenser and temperature sensor probe, after which 183 g of potassium acetate (Sigma Aldrich) were added thereto. introduced into The reaction mixture was heated to 80° C., kept under stirring for 2 h, then cooled to 25° C. and filtered using a centrifugal extractor RC30 (supplier: Robatel) equipped with a 6 μm porous filter made of polypropylene. and it was possible to obtain a polycondensation product, known as polymer B, containing 0.5% of insoluble substances.

Polymer B is characterized by a viscosity of 35 cps at 25° C., a positive charge density of 6.2 meq.g ⁻¹ , and a chloride content of 8% by weight of the polymer, which viscosity for an aqueous solution of Polymer B concentrated to 49.6% by weight has been decided; These values were determined according to the protocol as previously defined.

Example 2: Preparation of polymer P1 of diallyl dimethyl ammonium chloride characterized by a chloride content of less than 10% by weight of the polymer

In a 1 liter reactor equipped with a jacket, condenser, mechanical stirring mechanism and temperature sensor probe, the following components: 95 g of water, 135 g of diallyl dimethyl ammonium chloride (DADMAC) at a concentration of 64% by weight in water (SNF©) and 17 g of sodium hypophosphite at a concentration of 50% by weight in water were added. By mixing 13 g of water with 13 g of sodium hypophosphite (Sigma Aldrich) and 100 g of water with 13 g of sodium persulfate (Sigma Aldrich), respectively, the sodium hypophosphite solution and sodium A persulfate solution was prepared. 536 g of DADMAC (concentration 64% by weight in water), as well as sodium hypophosphite solution and sodium persulfate solution were added gradually over 2 hours to a 1 liter reactor.

The obtained homopolymer of DADMAC - known as polymer C - is characterized by a charge density of 6 meq.g ^-1 , a viscosity of 52 cps at 25° C., and a chloride content of 22% by weight of the polymer, this viscosity being 51 determined on aqueous solutions of polymer C concentrated to % by weight; These values were determined according to the protocol as previously defined.

Thereafter, 500 g of polymer C were introduced into a thermostatically controlled 1 liter reactor equipped with a jacket, magnetic stirrer, condenser and temperature sensor probe, into which 152 g of potassium acetate were added. The reaction mixture was heated to 85[deg.] C., then kept under stirring for 4 hours and then cooled to 30[deg.] C. The resulting mixture obtained was filtered using a centrifugal extractor RC30 (supplier: Robatel) equipped with a 6 μm porous filter made of polypropylene, and polycondensation product of DADMAC containing 1% insoluble material - Polymer D known as − can be obtained.

Polymer D is characterized by a viscosity of 53 cps at 25° C., a positive charge density of 5.4 meq.g ⁻¹ , and a chloride content of 7% by weight of the polymer, which viscosity for an aqueous solution of polymer D concentrated to 50% by weight has been decided; These values were determined according to the protocol as previously defined.

Example 3: Use of Water-Soluble Cationic Polymers as Agents for Clay Relief in Flow Test Concrete (slump test)

The performance of the water-soluble cationic polymer P1 of the present invention is evaluated (according to standard ASTM C1611) in the flow of cementitious compositions.

A “slump test” consists of placing a cone in the center of a plate, with a circle drawn on the plate, and filling the cone with the composition at its two bases open. and for which flow, screeding and demolding are measured. Thus, concrete flows more or less flows based on its fluidity. Spreading is the average of the distances along two perpendicular axes between the center of the circle and the end of the location formed by the poured concrete.

cementitious formulations

● Cement injected at a rate of 445 kg/m ³ (Supplier: Lafarge)

• Sand fed at a rate of 885 kg/m3 (normalized, density of 1485 kg/ ^m3 )

● bentonite clay

● water

● Polycarboxylic acid superplasticizer (SNF ⓒ Floset ^TM SH7)

is composed of

Several compositions (1-4) were prepared by mixing sand, cement, clay, water, superplasticizer and water-soluble cationic polymer for 5 minutes. The proportions of the different components, as well as the flow test results of the compositions, are summarized in Table 1.

composition One 2 3 4 cement (g) 450 450 450 450 water (g) 202.5 202.5 202.5 202.5 sand (g) 1350 1350 1350 1350 clay (g) 9.45 9.45 9.45 9.45 Superplasticizer (g) 7.5 7.5 7.5 7.5 Types of Cationic Polymers - Polymer B
(according to the invention) Polymer D
(according to the invention) CMA-2 of US Patent 2015/0065614
(comparison) cationic polymer (g) 0 0.189 0.199 0.189 Diffusion of concrete (mm) 240 310 320 310

Table 1: Characteristics of four compositions containing water-soluble cationic polymers and results of diffusion tests in concrete.

Based on Table 1, the water-soluble cationic polymer enables a gain of about 30% in terms of flow of concrete. The cationic polymers (Polymers B and D) from which the present invention is derived from the process with reduced levels of halide content have similar or superior performance levels to cationic polymers in the art, as reflected in document US 2015/0065614.

According to the example of US 2015/0065614, the polymer CMA-2 is characterized by a positive charge density of 7.2 meq/g, a chloride content of 25% by weight of the polymer, and a viscosity of 8.4 cps, which viscosity is concentrated to 50% by weight determined for an aqueous polymer solution.

Thus, lowering the halide content in the cationic water-soluble polymer does not result in a loss of activity of this polymer.

Example 4: Testing of Corrosion Induced by Various Cationic Polymers

The test consists of immersing metal cuts of various grades/alloys in a cationic polymer solution. A qualitative assessment of corrosion is performed based on a scale ranging from 0 to 10:

● 0 = No corrosion is observed

● 3 = some corrosion points (pitting-type) observed

● 5 = All metal cuts are moderately attacked

● 7 = All metal cuts are severely attacked

● 10 = All metal cuts are fully attacked.

The cut metal had the following dimensions: length: 100 mm, width: 30 mm, thickness: 1 mm. Prior to use, the metal cuts were washed to remove any solid material, and washed with acetone to remove any oil residues on the surfaces of these metal cuts. Thereafter, the cuts were immersed in a vessel containing an aqueous solution of cationic polymer at a concentration of 50% by weight and left immersed therein at 30° C. for 14 days.

The results of these corrosion tests performed on two different steels and in the presence of four different water-soluble cationic polymers (comparative and according to the invention) in solution are presented in Table 2.

cationic polymer steel grade wt% of chloride in polymer Assessment of corrosion Polymer B (comparative) carbon steel 8 4 Polymer D (according to the invention) carbon steel 7 4 CMA-2 (US 2015/0065614)
(comparison) carbon steel 26 8 Polymer C (comparative) carbon steel 22 7 Polymer B (according to the invention) Stainless Steel 304L 8 One Polymer D (according to the invention) Stainless Steel 304L 7 One CMA-2 (US 2015/0065614)
(comparison) Stainless Steel 304L 26 5

Table 2: Evaluation of corrosion induced by various different cationic polymers

Table 2 shows that in carbon steel grades, the water-soluble cationic polymer P1 derived from the process according to the invention induced a decrease in the corrosion level, which was twice that of the polymers (Polymers C and CMA-2) which presented a comparatively higher halide content. shows that it is smaller.

Thus, the use of polymer P1 according to the invention clearly leads to a reduction in the level of corrosion compared to the use of polymers in the art.

The same observations can be made regarding the use of cationic polymers on stainless steel 304L grades.

Claims (15)

A process for preparing an aqueous solution of a water-soluble cationic polymer P1, comprising:
the halide content is less than 10% by weight of the polymer, the viscosity at 25°C is less than 200 cps, the viscosity is determined for an aqueous solution of polymer P1 concentrated at 50% by weight, the positive charge density is at least 6 meq.g ^-1 ,
The method comprises the following successive steps:
a) adding at least one compound of formula (I) to an aqueous solution of at least one water-soluble cationic polymer P2 at a temperature of 0° C. to 120° C. to obtain a mixture, wherein the halide content is greater than 10% by weight of the polymer , the viscosity is less than 200 centipoise cps at 25° C., the viscosity is determined for an aqueous solution of polymer P2 concentrated to 50% by weight, the positive charge density is at least 6 meq.g ^-1 , the compound of formula (I) is defined by the formula: R ¹ -COO ^- Y ₁ ⁺ :
- R ¹ represents a hydrogen atom or a linear or branched saturated alkyl chain comprising 1 to 8 carbon atoms and which may contain one or more nitrogen and/or oxygen atoms, said chain of the formula -COR may be substituted by 1 to 4 carboxylate functional groups;
- Y ₁ ⁺ represents an alkali metal cation, an ammonium ion of the formula R ² -NH ₃ ⁺ or a quaternary ammonium of the formula R ³ -N ⁺ (R ⁴ )(R ⁵⁾ (R ⁶ );
- R represents an OH group or an O ^- Y ₂₊ group ^;
- Y ₂ ⁺ represents an alkali metal cation or an ammonium ion of the formula R ² —NH ₃ +;
- R ² represents a hydrogen atom or a linear or branched saturated alkyl chain comprising 1 to 4 carbon atoms;
- R ³ , R ⁴ , R ⁵ and R ⁶ represent, independently of each other, a linear or branched saturated alkyl chain comprising from 1 to 4 carbon atoms;
b) agitating the mixture obtained in step a) for at least 5 minutes to obtain a stirred mixture;
c) reducing the temperature of the stirred mixture obtained at the end of step b) at a temperature of -10°C to 50°C to obtain a cooled mixture; and
d) liquid/solid separation of the cooled mixture obtained at the end of step c) to obtain an aqueous solution of the cationic polymer P1
A method comprising a. The method of claim 1,
wherein said water-soluble cationic polymer P1 is characterized by a weight content of insoluble compounds of less than 2% relative to the total weight of said polymer. According to claim 1,
In step a), the ratio of the number of negative charges of the compound of formula (I) to the number of positive charges of the water-soluble cationic polymer P2 is 0.2:1 to 5:1. According to claim 1,
wherein the compound of formula (I) is selected from sodium formate, potassium formate, sodium acetate and potassium acetate. According to claim 1,
A process, wherein the liquid/solid separation step d) is a decantation or filtration process. According to claim 1,
wherein said water soluble cationic polymer P2 is derived from polymerization of one or more monomers of diallyldialkyl ammonium halide. According to claim 1,
wherein the water-soluble cationic polymer P2 is derived from polymerization of at least diallyl dimethyl ammonium chloride. According to claim 1,
wherein the water-soluble cationic polymer P2 is a polymer derived from the polymerization of at least one epihalohydrin with at least one secondary amine. According to claim 1,
wherein the water-soluble cationic polymer P2 is a polymer derived from the polymerization of epichlorohydrin and dimethylamine. 10. The method of claim 9,
The method of claim 1, wherein the stoichiometric ratio between the dimethylamine and the epichlorohydrin is 1:0.99 to 1:0.80. A process using the water-soluble cationic polymer P1 obtained by the process according to claim 1 , comprising:
wherein said water-soluble cationic polymer P1 is used in compositions based on inorganic mineral binders or gypsum derivatives, or
In the treatment of open, semi-closed, or closed aqueous circuits
How to use it as an additive. A process using the water-soluble cationic polymer P1 obtained by the process according to claim 1 , comprising:
A method of using said water-soluble cationic polymer P1 as a moderation agent for ameliorating the effect of clays in compositions based on inorganic mineral binders or gypsum derivatives. delete delete delete